This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A100475 #21 Feb 16 2025 08:32:55 %S A100475 1,2,3,5,11,13,14,34,931,7037,95017,3549221,75296795,3518502151, %T A100475 34778126848,747746329129,13428156340222,728260738568834, %U A100475 17205012007789762 %N A100475 Prime-th recurrence with reversal at each step. %C A100475 Starting at other than a(n) = 1, does this sequence ever go into a loop? %D A100475 Ball, W. W. R. and Coxeter, H. S. M. Mathematical Recreations and Essays, 13th ed. New York: Dover, pp. 14-15, 1987. %H A100475 Andrew Booker, <a href="https://t5k.org/nthprime/index.php#n-th">The Nth Prime Page</a> %H A100475 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Reversal.html">Reversal</a>. %H A100475 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/RossersTheorem.html">Rosser's Theorem</a>. %F A100475 a(n) = reversal(a(n-1)th prime). %e A100475 a(7) = 14 because a(6) = 13, the 13th prime is 41 and reversal(41) = 14. %t A100475 f[n_] := FromDigits[ Reverse[ IntegerDigits[ Prime[n]]]]; NestList[f, 1, 16] (* _Robert G. Wilson v_, Dec 02 2004 *) %t A100475 NestList[IntegerReverse[Prime[#]]&,1,19] (* _Harvey P. Dale_, May 02 2022 *) %Y A100475 Cf. A007097, A031877. %K A100475 nonn,base,more %O A100475 0,2 %A A100475 _Jonathan Vos Post_, Nov 22 2004 %E A100475 a(15)-a(16) from _Robert G. Wilson v_, Dec 02 2004 %E A100475 a(17)-a(18) from _Paul Zimmermann_, Dec 04 2004, computed thanks to Deléglise-Rivat's program; confirmed by Marc Deléglise, Dec 09 2004